Rank the Following Internet Marketing Techniques

[SEOnoob]

How do you rank the following free Internet marketing techniques according to efficiency in getting steady traffic to a website selling infoproducts? Something like ranking them from 1 to 5, one being the most efficient and 5 as the last one will help me a lot in completing the research I'm writing.

- forum posting
- article marketing
- link exchanges
- social networks (MySpace, FaceBook, etc.)
- having a blog with link to your site and leaving comments on other blogs

Thanks in advance.